1. Field of the Invention
This invention relates to a structural support used to attach outriggers to mobile equipment platforms which provides numerous advantages including ease of assembly, elimination of welding between the outrigger and the platform or truck frame, and the provision of a flexible joint between the outrigger and platform for attenuation of shear stresses. More particularly, the invention is concerned with a structural support having a pair of laterally spaced, vertically oriented, elongated brackets attached to and depending from the equipment platform, and a releaseable bolt assembly for securing the outrigger to the brackets.
2. Description of the Prior Art
It is known in the art of mobile booms such as cranes and the like to attach a sub-frame or equipment platform to the frame of a truck, and to provide the truck with ground-engaging outriggers to provide a sturdy operating base for the equipment. Heretofore, it has been customary to attach the outrigger to the truck by initially welding the outrigger to the equipment platform, and sliding the frame of the truck between the previously welded together platform and outrigger. Final attachment involves perforating the truck frame with bolt-receiving apertures, and bolting the outrigger to the frame of the truck. Although this means for attachment of an outrigger and platform to the truck frame provides a sturdy joint, the process of positioning the truck frame between the outrigger and equipment platform is awkward, perforation of the truck frame is not particularly desirable, the welded joint between the platform and outrigger is rigid and inflexible, and it is difficult to accommodate the welded structural support to truck frames of non-standard dimensions.
The difficulty in positioning the truck frame between the outrigger and platform arises because it is often desirable to have the dealer, rather than the manufacturer, attach the equipment platform and outrigger to a truck frame. In addition, it is also desirable to weld the outrigger to the equipment platform at the manufacturer's site, so that quality control of the welding joint can be assured. If the equipment platform and outrigger are pre-welded at the manufacturer's site, however, the dealer must have a facility for suspending the equipment platform, and for backing the truck frame between the outrigger and the platform. This obviously requires extensive dealer equipment which may not always be available. In addition, truck frames are available to either dealers or manufacturers in varying dimensions. If an outrigger is pre-welded to an equipment platform for attachment to a particular size of truck frame, the platform outrigger assembly cannot later be reconfigured for placement on a truck frame of a different size.
The joint between the outrigger and platform is subjected to flexing forces resulting from the vibrations and shock attendant the operation of the crane mounted on the truck. The joint is in effect a pivot point about which the platform tries to shift when the outrigger is firmly emplaced on the ground, and motion is emparted to the platform by the operation of the crane. Welded joints are inherently rigid, and if the outrigger is welded to the equipment platform, the welding joint must bear the entire shear stress caused by the pivoting action of the platform about the outrigger.
It would therefore be a real advancement in the art to provide a structural support for attachment of outriggers to mobile equipment platforms that will facilitate the process of attaching the equipment platform and outrigger to the frame of a truck, eliminate the need for perforating the truck frame with bolt-receiving apertures, attenuate the effect of at least some of the shear stress at the outrigger and platform joints, and will easily accommodate attachment of equipment platforms and outriggers to truck frames of non-standard dimensions.